Conventionally, a technique for acquiring three-dimensional data on a railroad area using a measurement vehicle equipped with a laser scanner to perform construction limit measurement or the like is provided.
For example, the following Patent Literature 1 discloses a three-dimensional data acquisition device including a first laser scanner and a second laser scanner. Specifically, the first laser scanner is a device configured to emit laser light to an object while rotating the laser light and to receive the reflected light in order to measure the distance to the object to be measured. The first laser scanner is installed on an upper part of a railroad vehicle such that a measurement cross section forming a rotation cross section of the laser light in an emission direction forms a vertical plane with respect to the travelling direction of the railroad vehicle. The second laser scanner is a device configured to emit laser light to the object while rotating the laser light and to receive the reflected light in order to measure the distance to the object. The second laser scanner is installed on the upper part of the railroad vehicle such that a measurement cross section forming a rotation cross section of the laser light in the emission direction forms a plane inclined at a predetermined angle in a substantially travelling direction with respect to the measurement cross section of the first laser scanner.